The German government has called on British Prime Minister Theresa May to present her government's plans about the future relationship between Britain and the European Union after it leaves the bloc.

A spokesman for German Chancellor Angela Merkel said Wednesday "it's important for us that Britain concretize its plans ... time is running out."

Merkel is meeting with May in Berlin on Friday.

The EU's Brexit negotiator, Michel Barnier, said last week that Britain has still not outlined its vision of future EU-U.K. relations at virtually the half-way mark of the Brexit negotiations.

Britain officially departs the EU on March 29 next year — the first member ever to leave. But the extraordinarily complex negotiations must be concluded this fall to allow time for parliaments of EU nations to ratify any deal.